The present invention relates to a system and method for promoting the healing of damaged animal tissue, including human tissue by propagation of an electric current flow through the tissue. In particular, the invention relates to a method for promoting the healing of bedsores and the like by propagation of an electric current flow through the damaged tissue.
U.S. Pat. No. 4,117,846 to Williams discloses a disposable skin conducting electrode assembly and electrode therefor for use on a patient. The electrode assembly comprises an electrolyte pad, an electrode and an adhesive pad.
It is taught in the above-mentioned patent that such an electrode can be used for various kinds of electrical treatments, including electrosurgery, medical diathermy (thermopenetration), and pain relief using transcutaneous nerve stimulation, aiding the setting and proper healing of broken bones and fractured vertebrae, and improving the curvature of the spine.
An electrode of this type can also be used for the transmission of an electrical impulse for directly stimulating a nerve or nerve pathway for restoring the physiological functions of a damaged nerve system. U.S. Pat. No. 4,117,846 teaches that an electrode assembly of this kind can be used to apply an electrical current for enhancing or promoting the healing of traumatized, injured or displaced tissue. The healing of bedsores or decubitis ulcers, surgical incisions, skin ulcerations, and lacerations is aided by long term application of high frequency current, and in some cases, by the application of low voltage DC current.
In contrast to U.S. Pat. No. 4,117,846, which mentions the application of high frequency current, U.S. Pat. No. 4,738,250 to Fulkerson, et al., discloses a medical electrical apparatus impressing a low frequency, bipolar, voltage wave form through spaced-apart electrodes, across a damaged area of living animal tissue to cause a low, bipolar, current to flow through the damaged area to increase the metabolic activity of viable cells in that area and hence to accelerate healing. The current flow is monitored and used to control the magnitude of the voltage wave to cause the magnitude of current flow to be within the desired parameters. The frequency, wave form and voltage of the impressed voltage-wave and the current flow are all below a level which can damage typical living cells.
According to U.S. Pat. No. 4,738,250, the above-described increase in metabolic activity results in at least the following positive benefits: accelerated production of adenosine triphosphate (ATP), increased synthesis of cell protein, improved cell membrane transport system, and accelerated production of collagen.
U.S. Pat. No. 4,738,250 further discloses that this electrical treatment signal reduces the concentration of free radicals that appear when cells are damaged. These free radicals are known to cause further damage by cell membrane disruption; and this reduction, done in accordance with the teachings of the invention, tends to reduce or eliminate this continuing damage without the current flow itself damaging the cells or otherwise insulting the living tissue being treated.
The electrical treatment signal disclosed by U.S. Pat. No. 4,738,250 is characterized by a current within a range of about 20 to 900 microamperes, resulting in the voltage of the treatment signal to be within a range of from zero to 30 volts. It is further disclosed that currents between 20 and 600 microamperes give good results, and that optimal results are obtained between 500 and 600 microamperes. Current flows approaching 1000 microamperes or 1 milliampere have proved destructive to cells in the pathway of such flow.
U.S. Pat. No. 4,738,250 also teaches a treatment signal having a treatment signal frequency within a range of about 0.1 to 15 Hz. However, in contrast to this relatively wide frequency range of 0.1 Hz to 15 Hz, U.S. Pat. No. 4,738,250 further discloses that the frequency of the wave form used can be varied from a very low frequency to a frequency slightly less than 1 Hz. Good results were obtained between 0.1 Hz and 0.9 Hz, and optimal results were obtained using a frequency of 0.5 Hz.
The form of the wave form applied is bipolar. In a first embodiment of the invention, the voltage of the treatment signal is increased in a linear fashion during each treatment signal time period until the current of the treatment signal attains its preselected value; and in a second embodiment of the invention, the voltage is increased nonlinearly, in an exponential fashion, during each treatment signal time period until the current attains its preselected value.
To the best of our knowledge, however, the treatment systems and methods described above have not been implemented in the treatment of bedsores. It may be stated with certainty that these prior art systems and methods are not common practice. It must be emphasized that there are no known, effective treatments for curing bedsores. According to T. McNamara, an expert in the prevention of amputation, treatment consists of wound management (keeping the affected area clean, administering antibiotics) combined with interventive procedures to improve the flow of blood, such as balloon angioplasty or bypass surgery (Dr. Thomas McNamara, xe2x80x9cNon-Surgical Techniques to Heal Foot Ulcers, Prevent Amputation and Relieve Leg Painxe2x80x9d, WebMD, 1999). Thus, the fact that the above-described systems and methods (applying electrical wave forms) have not been implemented is a clear indication of their ineffectiveness in the treatment of bedsores.
There is therefore a recognized need for, and it would be highly advantageous to have, an effective method for promoting the healing of bedsores and the like. Moreover, it would be of particular advantage to have amethod that can provide simple and inexpensive treatment by the propagation of an electric current flow through the damaged tissue. Finally, it would be highly advantageous to have a method that is mild and non-invasive, in view of the generally frail condition of those afflicted by bedsores.
According to the teachings of the present invention there is provided a method for the treatment of sores including the steps of: (a) situating a pair of spaced-apart electrodes in contact with healthy tissue on opposite sides of an area containing cells to be treated, and (b) externally inducing a percutaneous flow of electrical current between the electrodes through the area by establishing an external bipolar voltage wave form across the electrodes at a frequency of between 2 Hz and 10 Hz, wherein the sores are sores having substantially zero electrical activity.
According to further features in preferred embodiments of the invention described below, the frequency of the external bipolar voltage wave form across the electrodes is between 2 Hz and 5 Hz.
According to still further features in the described preferred embodiments, the external bipolar voltage wave form includes a positive voltage half cycle and a negative voltage half cycle, wherein at least one of the positive voltage half cycle and negative voltage half cycle contains at least two peaks.
In another aspect of the present invention there is provided a method for the treatment of sores including the steps of: (a) situating a pair of spaced-apart electrodes in contact with healthy tissue on opposite sides of an area containing cells to be treated, and (b) externally inducing a percutaneous flow of electrical current between the electrodes through the area by establishing a substantially cyclic voltage wave form across the electrodes, wherein the substantially cyclic voltage wave form includes a positive voltage half cycle and a negative voltage half cycle, and wherein at least one of the positive voltage half cycle and negative voltage half cycle contains at least two peaks, wherein the sores are sores having substantially zero electrical activity.
According to still further features in the described preferred embodiments, the sores having substantially zero electrical activity are bedsores.
According to still further features in the described preferred embodiments, the frequency of the external bipolar voltage wave form across the electrodes is between 16 Hz and 30 Hz.
Other aspects of the inventive treatment procedures are described more fully in my co-pending U.S. patent application, Ser. No. 09/593,399 filed Jun. 14, 2000, whose content is fully incorporated by reference for every purpose as if fully set forth herein.